Manufacture of separable fastener elements



Maid! 1943- J. ca. SOAVE 2,312, 94

MANUFACTURE SEPARABLE FASTENER ELEMENTS- Original Filed July 3, 1959 2 Sheets-Sheet 1 WITNESS Y INVENTOR Jofl/v 6. 50/7VE BY M We,

ATTORNEYS X WW iviawiz 2 @943 J 5, SQAVE 2,312,494

MANUFACTURE OF SEPARABLE FASTENER ELEMENTS Original Filed July 5, 1959 2 Sheets-Sheet 2 INVENTOR wnwgss 5 fy (fa/m 6. 504V:

I ATTORNEYS Patented Mar. 2, 1943 UNITED ATES PATENT John G. Soave, Long Island City, N. Y., assignor to Waldes Koh-I-Noor, Inc., New York, N. Y., a corporation of New York r i CE Original application July 3, 1939, Serial No.

282,686, now Patent No. 2,256,796, dated September 23, 1941.

Divided and this application.

March 31, 1941, Serial N0. 386,068

6 Claims.

This application is a division of my copending application, Serial No. 282,686, filed July 3, 1939, Patent No. 2,256,796, granted September 23, 1941.

The invention disclosed herein relates to separable fastener structures of the type in which a pair of flexible stringers or tapes have rows of interlocking elements attached along their adjacent edges, such elements being movedinto and out of interlocking engagement by a slider movable along the rows. The interlocking elements of this type of fastener usually comprise a head portion which projects beyond the edge of the associated stringer and which is provided on one side thereof with a locking projection and on its other side with a recess for cooperation with the locking projection of an adjacent interlocking element. Formed integrally with the head portion of each element are a pair of root or leg portions constituting clamping jaws by which the element is attached to the edge of the stringer or tape.

An object of the invention is toprovide an improved form of interlocking element whose manufacture will be relativelysimple and composed of relatively few operations and will involve a minimum amount of waste.

Another object of the invention is to provide interlocking elements of such improved construction that when they are attached to the stringers of the fastener they permit-an easy and substantially noiseless movement of the actuating slider, reduce the amount of wear on such slider and render the fastener structure extremely flexible.

Other objects as well as the novel features of the invention will become apparent from a perusal of the following description read in connection with the accompanying drawings, in which Fig. 1 is an enlarged fragmentary front elevation of a slide fastener structure having interlocking elements made in accordance with the invention, the slider and some of the elements being shown in section to illustrate more clearly novel details of construction; Fig. 2 is a sectional view taken along the line 22 of Fig. 1; Fig.3 is a plan view of the metallic strip from which the fastener elements are made and illustrates certain steps in the method of manufacturing such elements; Fig. 4 is a side elevational view, partly in section, of the die mechanism which may be employed in producing the illustrated interlocking elements and showing the shearing punch engaging the blank to cut out an interlocking element; Fig. 5 is a View similar to Fig. 4 and illustrates an advanced stage in the shearing stroke of the punch; Fig. 6 is an end view, greatly enlarged, of the portions.

provided on one of its flat side faces with a prov elements shown in Figs. 1 and 2; Fig. 7 is an enlarged view similar to Fig. 3 illustrating the method of manufacturing a modified form of fastener element; Fig. 8 is a plan view of a single element of the type illustrated in Fig. 7 and showing the element attached toa stringer; Fig. 9 is a side view of the parts illustrated in Fig'. 8; Fig. 10 is a plan view of a blank illustrating the steps of manufacturing another embodiment of the invention; Fig. 11 is a plan view of the type of element illustrated in Fig. 10 and showing it attached to a stringer tape and Fig. 12 is a side view of the parts illustrated in Fig. 11.

In the drawings, the numerals l and 2 designate the flexible stringers or tape supports of the fastener structure, such tapes being of the usual type and having attached thereto the series or rows 3 and 4 of interlocking elements. The interlocking elements in the opposed series are moved into and out of interlocking engagement by means of a slider 5. As is shown more clearly in Figs. 3 and 6 of the drawings, each fastener element comprises a head portion 6 having integrally formed therewith the leg or jaw portions 1 and 8 which are separated by a recess 9. Prior to the application of the element to its associated stringer, the legs 1 and 8 extend divergently from the head portion (see Fig. 3) to facilitate insertion and attachment of the beaded or reinforced edge of the stringer tape between such leg The head portion 6 of the element is jecting pin I0 and is provided on its opposite face with a complemental socket or recess H. The interlocking elements 3 and 4 are formed from a flat strip or ribbon l2 (see Fig. 3) made of metal of the desired character for use in forming such units, such strip preferably being of substantially the same width as the width of the elements with their legs spread divergently from the head portions thereof, as is illustrated in Fig. 3 of the drawings. It will be apparent, however, that the elements can be made from strips having other forms than that illustrated in Fig. 3 of the drawings. For example, a strip can be used which is wider than strip l2.

In manufacturing the interlocking elements 3 and d from the strip or ribbon of metallic material 12. the latter is advanced endwise through mechanism capable of forming and cutting out elements having the form of the element shown in only such portions of such mechanism being illustrated in Figs. 4 and 5 of the drawings of the instant case as are necessary for an understanding of the method of manufacturing such elements.

As described in my aforesaid application, the die.

mechanism includes a cupping Punch l6 and a shearing punch i1 positioned closely adjacent to one another and mounted for simultaneous reciprocating movement. The shearing punch I1 is advanced with respect to the cupping punch I. so that in its movements toward the die bed it is adapted to initially engage the inserted end of the strip i 2 and to start its cutting operation prior to the cupping operation of the cupping punch It. The cuppingpunch i6-engages the blank l2 to form the recesses or sockets i l in the upper face of the blank and at the same time forces the metal material displaced thereby in the formation of such recesses, into a die member ll disposed beneath the blank to form the outwardly projecting bosses or pins iii. In constructing the form of element illustrated in Figs. 1 to 3 and 6 of the drawings, the working end of the cupping punch It should be so formed that the recess II will include a vertically disposed and substantially rectangularly shaped side l9 (see Figs. 1 and 4), a bottom face extending from a point below the lower edge of the face 18 and inclining toward the latter at an angle of approximately 30 degrees from the horizontal (see Figs. 1, 2 and 4) and a U-shaped wall 2! (see Fig. 2) which inclines outwardl;-- and upwardly from the bottom edge of the face 20 and in a direction opposite to the face 20 at an angle of approximately 37 degrees from the horizontal and inclines outwardly and upwardly from the side edges of the face 20 at an angle of approximately 30 degrees from the vertical.

The material displaced by the cupping punch ii is forced by the latter into a recess formed in the die to produce the locking pin l0 which, by reason of the shape of the die, is provided with a forward edge 22 (see Fig. 4) which extends substantially perpendicularly to the blank and curved, inclined side and rear walls and is so dimensioned as to be capable of readily entering into a cooperating recess ll of an adjacent element in the fastener and to loosely engage with the latter, as is illustrated in Fig. lot the draw ings.

The shearing punch H, as has been mentioned, moves downwardly simultaneously with the cupping punch |5 though slightly in advance of the latter and in its downward movement cuts out a complete fastener element by a severing cut made across the blank or strip i2 by its front cutting edge 28 which is shaped similarly to the dotted line designated 23 in Fig. 3 of the drawings and cuts made along the lines 24 and 25 (see Fig. 3) by its angularly disposed rear cutting edges. The cut made by the front cutting edge of the punch H, as is illustrated by the dotted line 23 in Fig. 3 of the drawings, is convexly shaped in its central portion and concavely shaped on each side of such central portion, such cut forming the outer sides of laws 1 and 8 in their spread condition and the outer side of the head 6 of the fastener element. Thus the cut element in plan view will have the form indicated by the element drawn in full lines in Fig. 3 of the drawings. The bottom face 26 of the punch I1 is slightly concaved downwardly at the forward end thereof so that the convexly shaped portion of the front cutting edge thereof is slightly advanced from the remainder of such edge (see Figs. 4 and 5). The

punch l! is preferably made wider than the width of the strip or blanki2 so that portions of the side edges of the strip are left untouched to produce the edge portions 21," 21 on the jaws of the fastener element (see Figs. 2 and 3).

In the formation of the element, as the punch l1 descends, the advanced central portion of its front cutting edge engages with the strip l2 just in back of a previously formed socket ii and cooperates with the portion or wall 28 of the die to initially compress the metallic material of the strip therebetween before the punch has advanced to the extent where it will operate to shear the element from the strip. During this portion of the travel of the punch i1, when pressure is exerted on the strip l2 along the advanced portion of the front shearing edge, the material of the strip in the region of the socket ii is, by reason of this pressure, compressed to cause a slight tilting of the projection lfl from its initially formed position to the right, as viewed in Fig. 4, to cause the central portion of the inclined wall 2| of the socket H to become slightly concaved, as can be more clearly seen in Figs. 1 and 5 of the drawlugs, and to cause a thinning and increased density of the material in the head 5 of the element. as is shown in Fig. 6 of the drawings, the surface of the head of the element engaged by the concaved portion of the bottom face 26 of the punch taking'the form of such punch and being correspondingly convexly shaped. It will be apparent that the degree to which the metal in the head of the element will be compressed during such initial action of the punch H, will be controlled by the cupped configuration of the bottom face of the punch or, in other words, by the amount which the front cutting edge of the punch projects or is advanced from the under surface of the punch. Upon further downward movement of the punch, the complete element is sheared from the strip, the punch forcing the element through the die hole and depositing it upon suitable discharge mechanism. The completed element is then fed to suitable mechanism for clamping the element to a tape. As a result of the clamping operation. the outer concavely shaped sides of the jaws 7 end 8 of 'the element (see Fig. 3) are straightened so that the outer side edges of the jaws become straight throughout and in parallel relation (see Fig. 2). The angularly disposed rear sides 24 and 25 of the jaws l and 8 are also brought into position so that ihey are disposed at right angles to the outer side edges of the element jaws and form definitely defined transverse shoulders upon which the slider is enabled to obtain a firm grip, as is illustrated in Figv 2 of the drawings. The chamfered sides 21, 21 of the element enable the slider to move easily relative to the element and at the same time prevent unnecessary wear on the in terior surfaces of the slider, thereby assuring a perfect fit of the slider and positive operation of the elements throughout the life of the slider.

The particular form of the projection or looking pm Hi and the recess ll of the element may be varied somewhat dependent on the size of the element required For example, in Figs. 7 to 12 of the drawings, therear'e shown two forms of elements which have been found satisfactory for elements smaller in size than that illustrated in Figs. 1 to 6 of the drawings. In both of these modified forms, the headof the element is made substantially in the shape of a semi-circle in order to reduce the,width of the element to its smallestpractical dimension, while at the same time not weakening the element along the lines of juncture of such head portion with the jaws thereof, 1. e., along the lines between the points 30, 30 indicated in Figs. '7 and of the drawings, where the maximum bending stresses take place in the formation of the element into its completed form. By forming the interior sides 3! of the jaws or legs of the elements so that when the elements are completed and clamped on the tapes, as is illustrated in Figs. 8 and 11, such interior sides and the interior side of the head portions of the elements form a substantial circle, the maximum amount of strength along the lines of juncture 36, 3'.- of the jaws with the head of the elements will be attained. In theelement illustrated in Fig. '7, the radii of curvature of the interior sides of the jaws thereof are the same but are slightly diiferent from the radius ofcurvature of the interior side 32 of the head portion of the element, being smaller than the latter so that a greater thickness of cord and tape will be enclosed between the jaws of the element. In the form of the element shown in Fig. 10, the radius of curvature of each of the interior edges of the jaws is the same as the radius of curvature of the interior side of the head portion of the element so that when the element is clamped on a tape the interior sides thereof form a substantially perfeet circle, as is illustrated in Fig. 11 of the drawings. Like the element shown in Figs. 1 to 6 of the drawings; the elements illustrated in Figs. 7 to 12 have the exterior sides of the jaws formed concavely so that in their final form after being clamped on to the tape such edges will be straight throughout, with the outer side edges of the jaws of each element in parallel relation. In the two modifications illustrated, it is desirable that the faces 33 and 34 of the recesses thereof adjacent to the outer edges of the head portions be substantially similar in shape to the latter and that the surfaces 35 and 36 of the projections thereof be arcuately shaped, as is illustrated. Like the first described form, however, the faces 33 and 36 of the recesses thereof are concaved in the direction of their depths and the head portions thereof are reduced in thickness by the compressing thereof during the shearing operation, as has been previously explained. With the elements so formed and clamped to a pair of cooperating tapes, the fastener structure will have a maximum flexibleness and can be bent readily without disturbing the interlocked condition of the elements, such elements by reason of the denser material at their working end portions being more resistant to wear.

I claim:

l. A separable fastener element comprising a head portion and jaw portions, the head portion of said element being substantially semi-circularly shaped and having a recess in one face and a pin projecting from the opposite face, the outer end portion of said pin being adapted to engage with the recess of another element, said pin in cross-sectional area substantially less than the area of said recess and said recess having a foredges being chamfered, and the interior sides ofsaid head and jaw portions being substantially circular in form.

2. An interlocking element for a separable fastener comprising a. head portion and spread jaws integrally connected to said head portion, said head portion having a recess in one face and a pin projecting from the opposite face, the outer end portion of said pin being adapted to engage with the recess of another element, said pin in the recess engaging portion thereof having a cross-sectional area substantially less than the area of said recess and said recess having a forward wall which curves upwardly in a concave fashion from the bottom of the recess, the thickness of said head portion between such faces gradually decreasing towards the outer end thereof and the outer side surfaces of said iaws being concaved in the direction of their lengths.

3. An element such as is defined in claim 2, in which the recess in said head portion has an inner face disposed substantially vertically to the length of the element, a bottom face inclined away from said inner face and a U-shaped forward end Wall inclining upwardly and outwardly from said bottom face, the central portion of said U-shaped end wall being concaved in a direction transverse to its depth.

4. An element such as is defined in claim 2, in

which the outer side surfaces of said jaws are connected to outer sides extending in parallelism with the central longitudinal line of the element and includes end surfaces connected to and extending at aangle to said outer sides.

5. An element such as is defined in claim 2, in which the face thereof bearing the recess is convexly shaped from the region ofjuncture of the jaws thereof to the outer end of said head portion.

6. An element such as is defined in claim 2, in which said pin comprises a convexly curved surfacedisposed substantially vertically to the adjacent face of the element and a convexly curved surface inclined with respect to such face, both of said surfaces being substantially U-shaped.

JOHN G. SOAVE. 

